diff --git a/GFS_layer/GFS_typedefs.F90 b/GFS_layer/GFS_typedefs.F90
index 1721adb6..1c7905c1 100644
--- a/GFS_layer/GFS_typedefs.F90
+++ b/GFS_layer/GFS_typedefs.F90
@@ -3918,6 +3918,8 @@ subroutine diag_create (Diag, IM, Model)
     allocate (Diag%pfr(IM,Model%levs))
     allocate (Diag%pfs(IM,Model%levs))
     allocate (Diag%pfg(IM,Model%levs))
+    allocate (Diag%column_moles_co2_per_square_meter(IM))
+    allocate (Diag%column_moles_dry_air_per_square_meter(IM))
 
     !--- 3D diagnostics
     if (Model%ldiag3d) then
@@ -3935,8 +3937,6 @@ subroutine diag_create (Diag, IM, Model)
       allocate (Diag%wu2_shal(IM,Model%levs))
       allocate (Diag%eta_shal(IM,Model%levs))
       allocate (Diag%co2(IM,Model%levs))
-      allocate (Diag%column_moles_co2_per_square_meter(IM))
-      allocate (Diag%column_moles_dry_air_per_square_meter(IM))
 
       !--- needed to allocate GoCart coupling fields
       allocate (Diag%upd_mf (IM,Model%levs))